Homovanillic acid in human cerebrospinal fluid.--Its concentration gradient and reduced levels in patients with epilepsy

The homovanillic acid (HVA) concentrations in the lumbar cerebrospinal fluid (CSF) were determined in 38 epileptic and 39 control patients. The mean concentration of HVA was 23.9 ng/ml +/- 2.8 SEM for the epileptic group and 30.2 ng/ml +/- 2.1 SEM for the control group, respectively. Thus, HVA was significandly reduced in the patients with epilepsy compared with the controls. The mean HVA in the female patients was higher than in the male patients in both groups but this failed to reach statistical significance. There was no apparent relationship between the degree of reduced HVA concentration and other clinical indexes of the epilepsy (age, type and frequency of seizures, and anticonvulsant medication). For the determination of concentration gradient of HVA three fractions of the spinal CSF were obtained from 11 patients. A pronounced gradient of HVA concentration was found with a ratio of 1 : 1.46 : 1.97 for the first, second and third fractions. This suggests that a standardized conditions for collecting CSF should be employed to study HVA levels in humans.